Police said a 17-year-old male has been arrested and is currently in custody assisting officers with their inquiries.

There has been an outpouring of grief on social media.

The City of Armagh High School expressed sadness at the tragic loss of a former head girl.

A statement on the school's Facebook page said: " The school mourns the passing of past pupil and Head Girl Lesley-Ann McCarragher who passed away early this morning.

"So many people from the school have fond memories of Lesley-Ann and we would like to send our condolences to her family and many friends at this time."

Jackey Mitchell wrote on Facebook: "Lesley-Ann was one of the nicest most beautiful people I had the pleasure of knowing."

Victoria McCarten added: "Thoughts and prays with her family at this sad sad time. I remember playing hockey with Lesley-Ann through school. Such a pleasant girl. Xx"

Police Service of Northern Ireland Detective Inspector Brian Foster has appealed for any witnesses, particularly anyone with information about a white Saab car, to contact the non-emergency 101 number.